Embodiments of the present invention generally relate to a filter. More specifically, a multistage filter for use with a gas analyzer such as a hand held gas analyzer.
Gas powered vehicles produce emissions of various gases leading to pollution of the air. Most states require yearly vehicle inspections as part of the privilege in driving in their states. However, some states, such as California, have required stricter emission standards for the vehicles of their citizens. Thus, testing facilities and repair garages are performing more tests as the regulations become tighter.
In the past, only hydrocarbons (HC) and carbon monoxide (CO) had to be measured, but stricter regulations require the measurement of oxygen (O2), carbon dioxides (CO2) and nitrous oxides (NOx), as well. The vehicle must pass inspection, including emissions testing, in order to obtain a valid inspection sticker. If the vehicle fails, then it must be repaired before it will pass inspection. In the repair process, a mechanic must be able to determine if the repair of the gas emission system was successful.
Gas analyzers have been developed in order to help the mechanic diagnose the emission problems. Large platform analyzers were originally developed to measure the emission gases and were moved around on carts. However, large platform analyzers are too large for small garages to use and store. Additionally, the large platform analyzers are typically very expensive for small repair garages to own.
xe2x80x9cPortablexe2x80x9d gas analyzers were subsequently developed to be used for repair purposes. While the portable gas analyzers were smaller, they still weigh between twenty-thirty pounds and are too large to be held in the operator""s hands. Because the portable analyzers were still big, they required a big pump to move the emission gases throughout the analyzer for measuring, and a large filtering device to filter the particulate and moisture from the emission gases. The big pump also required a large power source, thus increasing the weight of the portable gas analyzer. Additionally, the portable gas analyzer has a large chassis to hold the various components together. The large size of the chassis increases the weight of the analyzer.
As the analyzer operates, emission gases including condensation from the line (due to a hot emission source traveling in hoses that are at ambient temperature) are filtered through a filter. However, the analyzer can have many filters that require additional hoses so that additional contamination and condensation leading to false readings can occur.
In order to circulate the emission gases, a pump is utilized. However, the pump can be big because of the size of the analyzer. The pump is solidly mounted onto the chassis. Additionally, the pump vibrates, thereby, transmitting the vibration to the operator, and making it uncomfortable for the operator to use the analyzer.
In another aspect of the invention, a method for filtering gases in a gas analyzer device is provided including receiving a gas in a filter holder having an upper portion and a lower portion. The gas passes through a first filter element located in the upper portion of the filter holder and a second filter element located in the lower portion of the filter holder.
Therefore, there is a need for an analyzer that can be lightweight, compact, and portable. There is also a need for an integrated multistage filter system to reduce contamination and condensation. Additional needs include an analyzer that can notify the operator that it is in the wrong orientation for better purging and for an analyzer with reduced vibration from the pump so that the analyzer is more comfortable to use. There is a further need for an analyzer that can purge and recalibrate (xe2x80x9czero outxe2x80x9d).
Embodiments of the present invention generally provide for an analyzer that is portable, lightweight and compact and includes a multistage filter. The analyzer can have an orientation component, can have less vibration, and can purge and/or zero manually or automatically.
In one aspect, the invention provides a multi-stage filtration assembly for a gas analyzer system including a filter holder forming a chamber having a lower portion and an upper portion. A filter element having a first filter and a second filter is located in an upper portion and lower portion of the chamber, respectively. The filtration assembly may also provide the first filter as a two stage particulate filter comprising an inner filter element and an outer filter element.
In another aspect of the invention, a method for filtering gasses in a gas analyzer device is provided including receiving a gas in a filter holder having an upper portion and a lower portion. The gas passes through a first filter element located in the upper portion of the filter holder and a second filter element located in the lower portion of the filter holder.
In yet another aspect of the invention, a multi-stage filtration system for a gas analyzer system is provided including a means for receiving a gas in a filter holder having an upper portion and a lower portion, a means for passing the gas through a first filter element located in an upper portion of the filter holder, and a means for passing the gas through a second filter element located in the lower portion of the filter holder.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described below and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.